as…as and as much/many as

as…as is used to say things are equal in some way. It also has another variant structures.
1. negative structure. After not, we can use so…as instead of as…as.
   She's not as/so kind as he is.
2. as…as+ adj/adv
   You are as beautiful as ever. Please come back as soon as possible.
3. as much/many…as  to talk about quantity.
  We need as much food as possible.
  I ate as much as I could.(without following nouns)
4. as much as 80kg means the large amount/quantity, or as little as 80kg means the small amount/quantity.
  Some of these pigs can weight as much as 300kg.
5. half/twice/three times+as…as
  It took twice as long as I expected.
6. (not) nearly, almost, just, nothing like, every bit,exactly, not quite +as …as
  He's not quite as tired as I was yesterday.

Also some tips we need to pay attention.
1. pronouns after as.
   She doesn't speak English as well as me.(informal style: we can use object pronouns)
   She doesn't speak English as well as I do.(formal style: we prefer subject +verb)
2. when is used with two infinitives, the second is often without to.
    It's as easy to do it right as (to) do it wrong.
3. In as…as-clauses, a present tense is often used to refer to the future, and a past tense can have a conditional meaning.
   I'll get there as soon as you do.